An automatic light control based on a photosensor is described in the patent application publication DE 19820348. For this purpose, a highly sensitive photosensor is provided in the motor vehicle, which is aligned forwards in the direction of driving. The headlights of an oncoming motor vehicle hit the photosensor when a motor vehicle is approaching, and the high beam or bright headlights are switched off. If a sufficiently low light intensity is again detected by the photosensor when the oncoming motor vehicle has passed by the driver's own motor vehicle and is outside the recording range of the photosensor, then the high beam headlights are switched back on again.
With this very simple method, only the light intensity is measured, but not the type of “light source” which is classified as ambient light, reflector, motor vehicle headlights, street lighting etc. This can cause erroneous functioning of the lighting control.